Featured Image placeholder if featured image is blank

                        
                          <?php if(has_post_thumbnail()): ?>
<!--This is what you want to see if the there is a featured image-->
<img src="<?php the_post_thumbnail_url(); ?> " >

<?php else: ?>
no image
<!--This is what you want to see if the there is NOT a featured image-->
<!--If you do not want to see anything then do not add any code here-->
<?php endif; ?>